Using the --skip-covered option on an HTML report with 100% coverage
would cause a “No data to report” error, as reported in issue 549. This is
now fixed; thanks, Loïc Dachary.

If-statements can be optimized away during compilation, for example, if 0:
or if __debug__:. Coverage.py had problems properly understanding these
statements which existed in the source, but not in the compiled bytecode.
This problem, reported in issue 522, is now fixed.

If you specified --source as a directory, then coverage.py would look for
importable Python files in that directory, and could identify ones that had
never been executed at all. But if you specified it as a package name, that
detection wasn’t performed. Now it is, closing issue 426. Thanks to Loïc
Dachary for the fix.

If you started and stopped coverage measurement thousands of times in your
process, you could crash Python with a “Fatal Python error: deallocating
None” error. This is now fixed. Thanks to Alex Groce for the bug report.

On PyPy, measuring coverage in subprocesses could produce a warning: “Trace
function changed, measurement is likely wrong: None”. This was spurious, and
has been suppressed.

Previously, coverage.py couldn’t start on Jython, due to that implementation
missing the multiprocessing module (issue 551). This problem has now been
fixed. Also, issue 322 about not being able to invoke coverage
conveniently, seems much better: jython-mcoveragerunmyprog.py works
properly.

Let’s say you ran the HTML report over and over again in the same output
directory, with --skip-covered. And imagine due to your heroic
test-writing efforts, a file just acheived the goal of 100% coverage. With
coverage.py 4.3, the old HTML file with the less-than-100% coverage would be
left behind. This file is now properly deleted.

Some environments couldn’t install 4.3, as described in issue 540. This is
now fixed.

The check for conflicting --source and --include was too simple in a
few different ways, breaking a few perfectly reasonable use cases, described
in issue 541. The check has been reverted while we re-think the fix for
issue 265.

Special thanks to Loïc Dachary, who took an extraordinary interest in
coverage.py and contributed a number of improvements in this release.

Subprocesses that are measured with automatic subprocess measurement used
to read in any pre-existing data file. This meant data would be incorrectly
carried forward from run to run. Now those files are not read, so each
subprocess only writes its own data. Fixes issue 510.

The coveragecombine command will now fail if there are no data files to
combine. The combine changes in 4.2 meant that multiple combines could lose
data, leaving you with an empty .coverage data file. Fixes
issue 525, issue 412, issue 516, and probably issue 511.

Branch coverage could misunderstand a finally clause on a try block that
never continued on to the following statement, as described in issue
493. This is now fixed. Thanks to Joe Doherty for the report and Loïc
Dachary for the fix.

A while loop with a constant condition (while True) and a continue
statement would be mis-analyzed, as described in issue 496. This is now
fixed, thanks to a bug report by Eli Skeggs and a fix by Loïc Dachary.

While loops with constant conditions that were never executed could result
in a non-zero coverage report. Artem Dayneko reported this in issue
502, and Loïc Dachary provided the fix.

The HTML report now supports a --skip-covered option like the other
reporting commands. Thanks, Loïc Dachary for the implementation, closing
issue 433.

Options can now be read from a tox.ini file, if any. Like setup.cfg, sections
are prefixed with “coverage:”, so [run] options will be read from the
[coverage:run] section of tox.ini. Implements part of issue 519.
Thanks, Stephen Finucane.

Specifying both --source and --include no longer silently ignores the
include setting, instead it fails with a message. Thanks, Nathan Land and
Loïc Dachary. Closes issue 265.

The Coverage.combine method has a new parameter, strict=False, to
support failing if there are no data files to combine.

When forking subprocesses, the coverage data files would have the same random
number appended to the file name. This didn’t cause problems, because the
file names had the process id also, making collisions (nearly) impossible.
But it was disconcerting. This is now fixed.

Programs that set Unicode configuration values could cause UnicodeErrors when
generating HTML reports. Pytest-cov is one example. This is now fixed.

Prevented deprecation warnings from configparser that happened in some
circumstances, closing issue 530.

Corrected the name of the jquery.ba-throttle-debounce.js library. Thanks,
Ben Finney. Closes issue 505.

Testing against PyPy 5.6 and PyPy3 5.5.

Switched to pytest from nose for running the coverage.py tests.

Renamed AUTHORS.txt to CONTRIBUTORS.txt, since there are other ways to
contribute than by writing code. Also put the count of contributors into the
author string in setup.py, though this might be too cute.

Since concurrency=multiprocessing uses subprocesses, options specified on
the coverage.py command line will not be communicated down to them. Only
options in the configuration file will apply to the subprocesses.
Previously, the options didn’t apply to the subprocesses, but there was no
indication. Now it is an error to use --concurrency=multiprocessing and
other run-affecting options on the command line. This prevents
failures like those reported in issue 495.

BACKWARD INCOMPATIBILITY: the coveragecombine command now ignores an
existing .coverage data file. It used to include that file in its
combining. This caused confusing results, and extra tox “clean” steps. If
you want the old behavior, use the new coveragecombine--append option.

The concurrency option can now take multiple values, to support programs
using multiprocessing and another library such as eventlet. This is only
possible in the configuration file, not from the command line. The
configuration file is the only way for sub-processes to all run with the same
options. Fixes issue 484. Thanks to Josh Williams for prototyping.

Using a concurrency setting of multiprocessing now implies
--parallel so that the main program is measured similarly to the
sub-processes.

The internal attribute Reporter.file_reporters was removed in 4.1b3. It
should have come has no surprise that there were third-party tools out there
using that attribute. It has been restored, but with a deprecation warning.

When running your program, execution can jump from an exceptX: line to
some other line when an exception other than X happens. This jump is no
longer considered a branch when measuring branch coverage.

When measuring branch coverage, yield statements that were never resumed
were incorrectly marked as missing, as reported in issue 440. This is now
fixed.

During branch coverage of single-line callables like lambdas and generator
expressions, coverage.py can now distinguish between them never being called,
or being called but not completed. Fixes issue 90, issue 460 and
issue 475.

The HTML report now has a map of the file along the rightmost edge of the
page, giving an overview of where the missed lines are. Thanks, Dmitry
Shishov.

The HTML report now uses different monospaced fonts, favoring Consolas over
Courier. Along the way, issue 472 about not properly handling one-space
indents was fixed. The index page also has slightly different styling, to
try to make the clickable detail pages more apparent.

Missing branches reported with coveragereport-m will now say ->exit
for missed branches to the exit of a function, rather than a negative number.
Fixes issue 469.

coverage--help and coverage--version now mention which tracer is
installed, to help diagnose problems. The docs mention which features need
the C extension. (issue 479)

Officially support PyPy 5.1, which required no changes, just updates to the
docs.

The Coverage.report function had two parameters with non-None defaults,
which have been changed. show_missing used to default to True, but now
defaults to None. If you had been calling Coverage.report without
specifying show_missing, you’ll need to explicitly set it to True to keep
the same behavior. skip_covered used to default to False. It is now None,
which doesn’t change the behavior. This fixes issue 485.

It’s never been possible to pass a namespace module to one of the analysis
functions, but now at least we raise a more specific error message, rather
than getting confused. (issue 456)

The coverage.process_startup function now returns the Coverage instance
it creates, as suggested in issue 481.

Make a small tweak to how we compare threads, to avoid buggy custom
comparison code in thread classes. (issue 245)

yieldfrom and await were considered returns from functions, since
they could tranfer control to the caller. This produced unhelpful “missing
branch” reports in a number of circumstances. Now they no longer are
considered returns.

In unusual situations, a missing branch to a negative number was reported.
This has been fixed, closing issue 466.

The XML report now produces correct package names for modules found in
directories specified with source=. Fixes issue 465.

Branch analysis has been rewritten: it used to be based on bytecode, but now
uses AST analysis. This has changed a number of things:

More code paths are now considered runnable, especially in
try/except structures. This may mean that coverage.py will
identify more code paths as uncovered. This could either raise or lower
your overall coverage number.

When combining data files, unreadable files will now generate a warning
instead of failing the command. This is more in line with the older
coverage.py v3.7.1 behavior, which silently ignored unreadable files.
Prompted by issue 418.

The –skip-covered option would skip reporting on 100% covered files, but
also skipped them when calculating total coverage. This was wrong, it should
only remove lines from the report, not change the final answer. This is now
fixed, closing issue 423.

In 4.0, the data file recorded a summary of the system on which it was run.
Combined data files would keep all of those summaries. This could lead to
enormous data files consisting of mostly repetitive useless information. That
summary is now gone, fixing issue 415. If you want summary information,
get in touch, and we’ll figure out a better way to do it.

Test suites that mocked os.path.exists would experience strange failures, due
to coverage.py using their mock inadvertently. This is now fixed, closing
issue 416.

Importing a __init__ module explicitly would lead to an error:
AttributeError:'module'objecthasnoattribute'__path__', as reported
in issue 410. This is now fixed.

Code that uses sys.settrace(sys.gettrace()) used to incur a more than 2x
speed penalty. Now there’s no penalty at all. Fixes issue 397.

Pyexpat C code will no longer be recorded as a source file, fixing
issue 419.

The source kit now contains all of the files needed to have a complete source
tree, re-fixing issue 137 and closing issue 281.

Reporting on an unmeasured file would fail with a traceback. This is now
fixed, closing issue 403.

The Jenkins ShiningPanda plugin looks for an obsolete file name to find the
HTML reports to publish, so it was failing under coverage.py 4.0. Now we
create that file if we are running under Jenkins, to keep things working
smoothly. issue 404.

Kits used to include tests and docs, but didn’t install them anywhere, or
provide all of the supporting tools to make them useful. Kits no longer
include tests and docs. If you were using them from the older packages, get
in touch and help me understand how.

py.test--cov can write empty data, then touch files due to --source,
which made coverage.py mistakenly force the data file to record lines instead
of arcs. This would lead to a “Can’t combine line data with arc data” error
message. This is now fixed, and changed some method names in the
CoverageData interface. Fixes issue 399.

CoverageData.read_fileobj and CoverageData.write_fileobj replace the
.read and .write methods, and are now properly inverses of each other.

When using report--skip-covered, a message will now be included in the
report output indicating how many files were skipped, and if all files are
skipped, coverage.py won’t accidentally scold you for having no data to
report. Thanks, Krystian Kichewko.

Coverage.py is now licensed under the Apache 2.0 license. See NOTICE.txt for
details. Closes issue 313.

The data storage has been completely revamped. The data file is now
JSON-based instead of a pickle, closing issue 236. The CoverageData
class is now a public supported documented API to the data file.

A new configuration option, [run]note, lets you set a note that will be
stored in the runs section of the data file. You can use this to annotate
the data file with any information you like.

Unrecognized configuration options will now print an error message and stop
coverage.py. This should help prevent configuration mistakes from passing
silently. Finishes issue 386.

In parallel mode, coverageerase will now delete all of the data files,
fixing issue 262.

Coverage.py now accepts a directory name for coveragerun and will run a
__main__.py found there, just like Python will. Fixes issue 252.
Thanks, Dmitry Trofimov.

The XML report now includes a missing-branches attribute. Thanks, Steve
Peak. This is not a part of the Cobertura DTD, so the XML report no longer
references the DTD.

Missing branches in the HTML report now have a bit more information in the
right-hand annotations. Hopefully this will make their meaning clearer.

All the reporting functions now behave the same if no data had been
collected, exiting with a status code of 1. Fixed fail_under to be
applied even when the report is empty. Thanks, Ionel Cristian Mărieș.

Plugins are now initialized differently. Instead of looking for a class
called Plugin, coverage.py looks for a function called coverage_init.

A file-tracing plugin can now ask to have built-in Python reporting by
returning “python” from its file_reporter() method.

Code that was executed with exec would be mis-attributed to the file that
called it. This is now fixed, closing issue 380.

The ability to use item access on Coverage.config (introduced in 4.0a2) has
been changed to a more explicit Coverage.get_option and
Coverage.set_option API.

The Coverage.use_cache method is no longer supported.

The private method Coverage._harvest_data is now called
Coverage.get_data, and returns the CoverageData containing the
collected data.

The project is consistently referred to as “coverage.py” throughout the code
and the documentation, closing issue 275.

Combining data files with an explicit configuration file was broken in 4.0a6,
but now works again, closing issue 385.

coveragecombine now accepts files as well as directories.

The speed is back to 3.7.1 levels, after having slowed down due to plugin
support, finishing up issue 387.

The original module-level function interface to coverage.py is no longer
supported. You must now create a coverage.Coverage object, and use
methods on it.

The coveragecombine command now accepts any number of directories as
arguments, and will combine all the data files from those directories. This
means you don’t have to copy the files to one directory before combining.
Thanks, Christine Lytwynec. Finishes issue 354.

HTML reports now include a timestamp in the footer, closing issue 299.
Thanks, Conrad Ho.

HTML reports now begrudgingly use double-quotes rather than single quotes,
because there are “software engineers” out there writing tools that read HTML
and somehow have no idea that single quotes exist. Capitulates to the absurd
issue 361. Thanks, Jon Chappell.

Plugin support is now implemented in the C tracer instead of the Python
tracer. This greatly improves the speed of tracing projects using plugins.

Coverage.py now always adds the current directory to sys.path, so that
plugins can import files in the current directory (issue 358).

If the config_file argument to the Coverage constructor is specified as
”.coveragerc”, it is treated as if it were True. This means setup.cfg is
also examined, and a missing file is not considered an error (issue 357).

Wildly experimental: support for measuring processes started by the
multiprocessing module. To use, set --concurrency=multiprocessing,
either on the command line or in the .coveragerc file (issue 117). Thanks,
Eduardo Schettino. Currently, this does not work on Windows.

A new warning is possible, if a desired file isn’t measured because it was
imported before coverage.py was started (issue 353).

The coverage.process_startup function now will start coverage measurement
only once, no matter how many times it is called. This fixes problems due
to unusual virtualenv configurations (issue 340).

Reports now use file names with extensions. Previously, a report would
describe a/b/c.py as “a/b/c”. Now it is shown as “a/b/c.py”. This allows
for better support of non-Python files, and also fixed issue 69.

The XML report now reports each directory as a package again. This was a bad
regression, I apologize. This was reported in issue 235, which is now
fixed.

A new configuration option for the XML report: [xml]package_depth
controls which directories are identified as packages in the report.
Directories deeper than this depth are not reported as packages.
The default is that all directories are reported as packages.
Thanks, Lex Berezhny.

When looking for the source for a frame, check if the file exists. On
Windows, .pyw files are no longer recorded as .py files. Along the way, this
fixed issue 290.

Empty files are now reported as 100% covered in the XML report, not 0%
covered (issue 345).

Regexes in the configuration file are now compiled as soon as they are read,
to provide error messages earlier (issue 349).

Officially support PyPy 2.4, and PyPy3 2.4. Drop support for
CPython 3.2 and older versions of PyPy. The code won’t work on CPython 3.2.
It will probably still work on older versions of PyPy, but I’m not testing
against them.

Plugins!

The original command line switches (-x to run a program, etc) are no
longer supported.

A new option: coverage report –skip-covered will reduce the number of
files reported by skipping files with 100% coverage. Thanks, Krystian
Kichewko. This means that empty __init__.py files will be skipped, since
they are 100% covered, closing issue 315.

You can now specify the --fail-under option in the .coveragerc file
as the [report]fail_under option. This closes issue 314.

The COVERAGE_OPTIONS environment variable is no longer supported. It was
a hack for --timid before configuration files were available.

The HTML report now has filtering. Type text into the Filter box on the
index page, and only modules with that text in the name will be shown.
Thanks, Danny Allen.

The textual report and the HTML report used to report partial branches
differently for no good reason. Now the text report’s “missing branches”
column is a “partial branches” column so that both reports show the same
numbers. This closes issue 342.

If you specify a --rcfile that cannot be read, you will get an error
message. Fixes issue 343.

The --debug switch can now be used on any command.

You can now programmatically adjust the configuration of coverage.py by
setting items on Coverage.config after construction.

A module run with -m can be used as the argument to --source, fixing
issue 328. Thanks, Buck Evan.

The regex for matching exclusion pragmas has been fixed to allow more kinds
of whitespace, fixing issue 334.

Made some PyPy-specific tweaks to improve speed under PyPy. Thanks, Alex
Gaynor.

In some cases, with a source file missing a final newline, coverage.py would
count statements incorrectly. This is now fixed, closing issue 293.

The status.dat file that HTML reports use to avoid re-creating files that
haven’t changed is now a JSON file instead of a pickle file. This obviates
issue 287 and issue 237.

Gevent, eventlet, and greenlet are now supported, closing issue 149.
The concurrency setting specifies the concurrency library in use. Huge
thanks to Peter Portante for initial implementation, and to Joe Jevnik for
the final insight that completed the work.

Options are now also read from a setup.cfg file, if any. Sections are
prefixed with “coverage:”, so the [run] options will be read from the
[coverage:run] section of setup.cfg. Finishes issue 304.

The report-m command can now show missing branches when reporting on
branch coverage. Thanks, Steve Leonard. Closes issue 230.

Omitting files within a tree specified with the source option would
cause them to be incorrectly marked as unexecuted, as described in
issue 218. This is now fixed.

When specifying paths to alias together during data combining, you can now
specify relative paths, fixing issue 267.

Most file paths can now be specified with username expansion (~/src, or
~build/src, for example), and with environment variable expansion
(build/$BUILDNUM/src).

Trying to create an XML report with no files to report on, would cause a
ZeroDivideError, but no longer does, fixing issue 250.

When running a threaded program under the Python tracer, coverage.py no
longer issues a spurious warning about the trace function changing: “Trace
function changed, measurement is likely wrong: None.” This fixes issue
164.

Static files necessary for HTML reports are found in system-installed places,
to ease OS-level packaging of coverage.py. Closes issue 259.

Source files with encoding declarations, but a blank first line, were not
decoded properly. Now they are. Thanks, Roger Hu.

The source kit now includes the __main__.py file in the root coverage
directory, fixing issue 255.

Wildcards in include= and omit= arguments were not handled properly
in reporting functions, though they were when running. Now they are handled
uniformly, closing issue 143 and issue 163. NOTE: it is possible
that your configurations may now be incorrect. If you use include or
omit during reporting, whether on the command line, through the API, or
in a configuration file, please check carefully that you were not relying on
the old broken behavior.

The report, html, and xml commands now accept a --fail-under
switch that indicates in the exit status whether the coverage percentage was
less than a particular value. Closes issue 139.

The reporting functions coverage.report(), coverage.html_report(), and
coverage.xml_report() now all return a float, the total percentage covered
measurement.

The HTML report’s title can now be set in the configuration file, with the
--title switch on the command line, or via the API.

Configuration files now support substitution of environment variables, using
syntax like ${WORD}. Closes issue 97.

Embarrassingly, the [xml]output= setting in the .coveragerc file simply
didn’t work. Now it does.

The XML report now consistently uses file names for the file name attribute,
rather than sometimes using module names. Fixes issue 67.
Thanks, Marcus Cobden.

Coverage percentage metrics are now computed slightly differently under
branch coverage. This means that completely unexecuted files will now
correctly have 0% coverage, fixing issue 156. This also means that your
total coverage numbers will generally now be lower if you are measuring
branch coverage.

When installing, now in addition to creating a “coverage” command, two new
aliases are also installed. A “coverage2” or “coverage3” command will be
created, depending on whether you are installing in Python 2.x or 3.x.
A “coverage-X.Y” command will also be created corresponding to your specific
version of Python. Closes issue 111.

The coverage.py installer no longer tries to bootstrap setuptools or
Distribute. You must have one of them installed first, as issue 202
recommended.

Running coverage.py under a debugger is unlikely to work, but it shouldn’t
fail with “TypeError: ‘NoneType’ object is not iterable”. Fixes issue
201.

On some Linux distributions, when installed with the OS package manager,
coverage.py would report its own code as part of the results. Now it won’t,
fixing issue 214, though this will take some time to be repackaged by the
operating systems.

The HTML report has slightly tweaked controls: the buttons at the top of
the page are color-coded to the source lines they affect.

Custom CSS can be applied to the HTML report by specifying a CSS file as
the extra_css configuration value in the [html] section.

Source files with custom encodings declared in a comment at the top are now
properly handled during reporting on Python 2. Python 3 always handled them
properly. This fixes issue 157.

Backup files left behind by editors are no longer collected by the source=
option, fixing issue 168.

If a file doesn’t parse properly as Python, we don’t report it as an error
if the file name seems like maybe it wasn’t meant to be Python. This is a
pragmatic fix for issue 82.

The -m switch on coveragereport, which includes missing line numbers
in the summary report, can now be specified as show_missing in the
config file. Closes issue 173.

When running a module with coveragerun-m<modulename>, certain details
of the execution environment weren’t the same as for
python-m<modulename>. This had the unfortunate side-effect of making
coveragerun-munittestdiscover not work if you had tests in a
directory named “test”. This fixes issue 155 and issue 142.

Now the exit status of your product code is properly used as the process
status when running python-mcoveragerun.... Thanks, JT Olds.

When installing into pypy, we no longer attempt (and fail) to compile
the C tracer function, closing issue 166.

When combining data files from parallel runs, you can now instruct
coverage.py about which directories are equivalent on different machines. A
[paths] section in the configuration file lists paths that are to be
considered equivalent. Finishes issue 17.

The number of partial branches reported on the HTML summary page was
different than the number reported on the individual file pages. This is
now fixed.

An explicit include directive to measure files in the Python installation
wouldn’t work because of the standard library exclusion. Now the include
directive takes precedence, and the files will be measured. Fixes
issue 138.

In order to help the core developers measure the test coverage of the
standard library, Brandon Rhodes devised an aggressive hack to trick Python
into running some coverage.py code before anything else in the process.
See the coverage/fullcoverage directory if you are interested.

The HTML report hotkeys now behave slightly differently when the current
chunk isn’t visible at all: a chunk on the screen will be selected,
instead of the old behavior of jumping to the literal next chunk.
The hotkeys now work in Google Chrome. Thanks, Guido van Rossum.

The HTML report now has hotkeys. Try n, s, m, x, b,
p, and c on the overview page to change the column sorting.
On a file page, r, m, x, and p toggle the run, missing,
excluded, and partial line markings. You can navigate the highlighted
sections of code by using the j and k keys for next and previous.
The 1 (one) key jumps to the first highlighted section in the file,
and 0 (zero) scrolls to the top of the file.

The --omit and --include switches now interpret their values more
usefully. If the value starts with a wildcard character, it is used as-is.
If it does not, it is interpreted relative to the current directory.
Closes issue 121.

Partial branch warnings can now be pragma’d away. The configuration option
partial_branches is a list of regular expressions. Lines matching any of
those expressions will never be marked as a partial branch. In addition,
there’s a built-in list of regular expressions marking statements which
should never be marked as partial. This list includes whileTrue:,
while1:, if1:, and if0:.

The coverage() constructor accepts single strings for the omit= and
include= arguments, adapting to a common error in programmatic use.

Modules can now be run directly using coveragerun-mmodulename, to
mirror Python’s -m flag. Closes issue 95, thanks, Brandon Rhodes.

coveragerun didn’t emulate Python accurately in one small detail: the
current directory inserted into sys.path was relative rather than
absolute. This is now fixed.

HTML reporting is now incremental: a record is kept of the data that
produced the HTML reports, and only files whose data has changed will
be generated. This should make most HTML reporting faster.

Pathological code execution could disable the trace function behind our
backs, leading to incorrect code measurement. Now if this happens,
coverage.py will issue a warning, at least alerting you to the problem.
Closes issue 93. Thanks to Marius Gedminas for the idea.

The C-based trace function now behaves properly when saved and restored
with sys.gettrace() and sys.settrace(). This fixes issue 125
and issue 123. Thanks, Devin Jeanpierre.

Source files are now opened with Python 3.2’s tokenize.open() where
possible, to get the best handling of Python source files with encodings.
Closes issue 107, thanks, Brett Cannon.

Syntax errors in supposed Python files can now be ignored during reporting
with the -i switch just like other source errors. Closes issue 115.

Installation from source now succeeds on machines without a C compiler,
closing issue 80.

Coverage.py can now be run directly from a working tree by specifying
the directory name to python: pythoncoverage_py_working_dirrun....
Thanks, Brett Cannon.

A little bit of Jython support: coverage run can now measure Jython
execution by adapting when $py.class files are traced. Thanks, Adi Roiban.
Jython still doesn’t provide the Python libraries needed to make
coverage reporting work, unfortunately.

Completely unexecuted files can now be included in coverage results, reported
as 0% covered. This only happens if the –source option is specified, since
coverage.py needs guidance about where to look for source files.

The XML report output now properly includes a percentage for branch coverage,
fixing issue 65 and issue 81.

Coverage percentages are now displayed uniformly across reporting methods.
Previously, different reports could round percentages differently. Also,
percentages are only reported as 0% or 100% if they are truly 0 or 100, and
are rounded otherwise. Fixes issue 41 and issue 70.

The precision of reported coverage percentages can be set with the
[report]precision config file setting. Completes issue 16.

Threads derived from threading.Thread with an overridden run method
would report no coverage for the run method. This is now fixed, closing
issue 85.

BACKWARD INCOMPATIBILITY: the --omit and --include switches now take
file patterns rather than file prefixes, closing issue 34 and issue 36.

BACKWARD INCOMPATIBILITY: the omit_prefixes argument is gone throughout
coverage.py, replaced with omit, a list of file name patterns suitable for
fnmatch. A parallel argument include controls what files are included.

The run command now has a --source switch, a list of directories or
module names. If provided, coverage.py will only measure execution in those
source files.

Various warnings are printed to stderr for problems encountered during data
measurement: if a --source module has no Python source to measure, or is
never encountered at all, or if no data is collected.

The reporting commands (report, annotate, html, and xml) now have an
--include switch to restrict reporting to modules matching those file
patterns, similar to the existing --omit switch. Thanks, Zooko.

The run command now supports --include and --omit to control what
modules it measures. This can speed execution and reduce the amount of data
during reporting. Thanks Zooko.

Since coverage.py 3.1, using the Python trace function has been slower than
it needs to be. A cache of tracing decisions was broken, but has now been
fixed.

Python 2.7 and 3.2 have introduced new opcodes that are now supported.

Python files with no statements, for example, empty __init__.py files,
are now reported as having zero statements instead of one. Fixes issue 1.

Reports now have a column of missed line counts rather than executed line
counts, since developers should focus on reducing the missed lines to zero,
rather than increasing the executed lines to varying targets. Once
suggested, this seemed blindingly obvious.

Line numbers in HTML source pages are clickable, linking directly to that
line, which is highlighted on arrival. Added a link back to the index page
at the bottom of each HTML page.

Programs that call os.fork will properly collect data from both the child
and parent processes. Use coveragerun-p to get two data files that can
be combined with coveragecombine. Fixes issue 56.

Coverage.py is now runnable as a module: python-mcoverage. Thanks,
Brett Cannon.

When measuring code running in a virtualenv, most of the system library was
being measured when it shouldn’t have been. This is now fixed.

Doctest text files are no longer recorded in the coverage data, since they
can’t be reported anyway. Fixes issue 52 and issue 61.

Jinja HTML templates compile into Python code using the HTML file name,
which confused coverage.py. Now these files are no longer traced, fixing
issue 82.

Source files can have more than one dot in them (foo.test.py), and will be
treated properly while reporting. Fixes issue 46.

Source files with DOS line endings are now properly tokenized for syntax
coloring on non-DOS machines. Fixes issue 53.

Unusual code structure that confused exits from methods with exits from
classes is now properly analyzed. See issue 62.

Asking for an HTML report with no files now shows a nice error message rather
than a cryptic failure (‘int’ object is unsubscriptable). Fixes issue 59.

Settings are now read from a .coveragerc file. A specific file can be
specified on the command line with –rcfile=FILE. The name of the file can
be programmatically set with the config_file argument to the coverage()
constructor, or reading a config file can be disabled with
config_file=False.

Fixed a problem with nested loops having their branch possibilities
mischaracterized: issue 39.

Coverage.py has a new command line syntax with sub-commands. This expands
the possibilities for adding features and options in the future. The old
syntax is still supported. Try “coverage help” to see the new commands.
Thanks to Ben Finney for early help.

Added parameters to coverage.__init__ for options that had been set on the
coverage object itself.

Added clear_exclude() and get_exclude_list() methods for programmatic
manipulation of the exclude regexes.

Added coverage.load() to read previously-saved data from the data file.

Improved the finding of code files. For example, .pyc files that have been
installed after compiling are now located correctly. Thanks, Detlev
Offenbach.

When using the object API (that is, constructing a coverage() object), data
is no longer saved automatically on process exit. You can re-enable it with
the auto_data=True parameter on the coverage() constructor. The module-level
interface still uses automatic saving.

HTML reports and annotation of source files: use the new -b (browser) switch.
Thanks to George Song for code, inspiration and guidance.

Code in the Python standard library is not measured by default. If you need
to measure standard library code, use the -L command-line switch during
execution, or the cover_pylib=True argument to the coverage() constructor.

Source annotation into a directory (-a -d) behaves differently. The
annotated files are named with their hierarchy flattened so that same-named
files from different directories no longer collide. Also, only files in the
current tree are included.

coverage.annotate_file is no longer available.

Programs executed with -x now behave more as they should, for example,
__file__ has the correct value.

.coverage data files have a new pickle-based format designed for better
extensibility.

Don’t try to predict whether a file is Python source based on the extension.
Extension-less files are often Pythons scripts. Instead, simply parse the
file and catch the syntax errors. Hat tip to Ben Finney.

Python 2.5 now fully supported. The method of dealing with multi-line
statements is now less sensitive to the exact line that Python reports during
execution. Pass statements are handled specially so that their disappearance
during execution won’t throw off the measurement.